Known in the art presently are dual electric layer capacitors with liquid electrolyte and electrodes made of diverse materials having high specific surface area (cf., e.g., U.S. Pat. No. 4,313,084 (1982) and U.S. Pat. No. 4,713,734 (1987), and DE U.S. Pat. No. 3,210420 (1983). Best results are attained when using the various activated carbons as the electrode materials. Specific capacitance of such capacitors exceeds 2 F/cu.cm, while use of aprotic electrolytes makes it possible to increase capacitor working voltage to 2-3 V (U.S. Pat. No. 4,697,224 (1987), Nat. Tech. Report, 180, 26, # 2, pp.220-230).
Closest to the proposed invention as to the technical essence and attainable effect is a DEL capacitor comprising two electrodes and liquid electrolyte (i.e., an aqueous alkali-metal hydroxide with a concentration of 3 to 7 mole/lit having a polarizable (negative) electrode made of a carbon fibrous material and a non-polarizable electrode made of nickel oxide. Maximum voltage of said capacitor equals 1.4 V and specific capacitance and specific energy, 46 F/cu.cm and 45 J/cu.cm, respectively (WO 97/07518 dated Feb. 27, 1997).